Traditionally, molded aerated frozen bars are manufactured by partially freezing an ice cream mix, water ice mix, or fruit juice mix in conventional batch or continuous freezers followed by pumping and filling the mix into molds of different shapes and sizes. During the last decade, a new generation of freezers has been developed which are equipped with pre-whippers that enable the mix to be pre-aerated before being partially frozen in the freezer. The molded products are usually quiescently frozen using a cold brine system at -30.degree. to -40.degree. C. If desired, after demolding, the molded products may be coated with chocolate or compound coating. Finally, the products are usually packaged and stored at about -30.degree. C. until transport and distribution.
This traditional process for manufacturing molded aerated frozen bars has limitations. For example, the partial freezing of the mix in the freezer, followed by quiescent freezing in the molds, leads to the formation of an icy texture, loss of air, and formation of large air cells in the product having a size range of about 110-185 microns (Arbuckle, W. S. Ice Cream, Fourth Edition, 1986, Van Nostrand Reinhold, New York, p 234). Additionally, shrinkage of the products is often a problem. Moreover, when eating the product, a very cold feeling in the mouth is experienced. Furthermore, it is difficult to achieve more than 20% overrun in water ice products and a typical overrun is from 0 to 20% and usually is about 5%. It is very difficult to achieve more than 80% overrun and almost impossible to achieve an overrun of 120% or higher in finished ice cream products using conventional manufacturing.
Currently, there is no process that can produce very finely aerated molded frozen bars (e.g., those having an average air cell size of less than 50 microns) that are smooth in texture, do not suffer from shrinkage, do not give a very cold feeling in the mouth, and have a uniform appearance without large air pockets on the surface. Moreover, no process can produce an overrun of more than 20% for water ice products and an overrun between about 80 to about 250% for ice cream products. The present invention provides a process and product which overcomes these disadvantages.